My '92 Toyota truck with the V6 3.0 engine is losing coolant, runs a little rough until warmed up and appears to have a lot of vapor in the exhaust. First thought was a blown head gasket, but there are none of the obvious indicators such as milky substance in the oil filler cap, no evidence of water in oil, no evidence of oil in the radiator and the coolant fluid does not bubble. Been six or eight months since the last oil change and the oil still looks good on the dipstick, but there is definitely a lot of what appear to be water vapor in the exhaust.

Tonight I borrowed the engine block test kit from O’Reilly and the test liquid changed color, but only slightly when compared to fresh liquid. It still looked bluish with perhaps a slightly green tint, but definitely not yellow. This is the first time I have used a block test kit. Thoughts? Does this definitely indicate a blown gasket? What are the recommended next steps to test? Cylinder compression check?

What other ways would coolant make its way into the combustion chamber?

I appreciate any thoughts. Thanks so much for the help.

1992 4x4 truck
3.0L 3VZE
5 speed

 

How much coolant do you need to add every time it gets driven??

All my blown Head gaskets I never got coolant in the oil

Just the exhaust looked like a crop duster just big clouds of smoke and about a gallon in 5 miles

 

Thanks for your comments. It used about 2 quarts coolant in the last three weeks, but it seems to be getting worse. Assuming it is a blown head gasket, then the next question is do I repair it. I have read a lot of threads bout swapping to a 3.4L, but a 24 year old truck with 186,000 miles has a lots of other worn parts. I have tried to keep up with the maintenance, but all of the rubber bushings, mounts, etc are still original and deteriorating along with all of the plastic components under the hood which are quite brittle.

 

There is also the possibility that coolant is leaking into the throttle body. This can be checked by looking under this cover held by 4 screws.

 

Thank you for the suggestion. I will check out that area of the throttle body.